drivers/hwmon/pmbus/zl6100.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Hardware monitoring driver for ZL6100 and compatibles
  *
  * Copyright (c) 2011 Ericsson AB.
  * Copyright (c) 2012 Guenter Roeck
  */

 #include <linux/bitops.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/i2c.h>
 #include <linux/ktime.h>
 #include <linux/delay.h>
 #include "pmbus.h"

 enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105,
 	     zl8802, zl9101, zl9117, zls1003, zls4009 };

 struct zl6100_data {
 	int id;
 	ktime_t access;		/* chip access time */
 	int delay;		/* Delay between chip accesses in uS */
 	struct pmbus_driver_info info;
 };

 #define to_zl6100_data(x)  container_of(x, struct zl6100_data, info)

 #define ZL6100_MFR_CONFIG		0xd0
 #define ZL6100_DEVICE_ID		0xe4

 #define ZL6100_MFR_XTEMP_ENABLE		BIT(7)

 #define ZL8802_MFR_USER_GLOBAL_CONFIG	0xe9
 #define ZL8802_MFR_TMON_ENABLE		BIT(12)
 #define ZL8802_MFR_USER_CONFIG		0xd1
 #define ZL8802_MFR_XTEMP_ENABLE_2	BIT(1)
 #define ZL8802_MFR_DDC_CONFIG		0xd3
 #define ZL8802_MFR_PHASES_MASK		0x0007

 #define MFR_VMON_OV_FAULT_LIMIT		0xf5
 #define MFR_VMON_UV_FAULT_LIMIT		0xf6
 #define MFR_READ_VMON			0xf7

 #define VMON_UV_WARNING			BIT(5)
 #define VMON_OV_WARNING			BIT(4)
 #define VMON_UV_FAULT			BIT(1)
 #define VMON_OV_FAULT			BIT(0)

 #define ZL6100_WAIT_TIME		1000	/* uS	*/

 static ushort delay = ZL6100_WAIT_TIME;
 module_param(delay, ushort, 0644);
 MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");

 /* Convert linear sensor value to milli-units */
 static long zl6100_l2d(s16 l)
 {
 	s16 exponent;
 	s32 mantissa;
 	long val;

 	exponent = l >> 11;
 	mantissa = ((s16)((l & 0x7ff) << 5)) >> 5;

 	val = mantissa;

 	/* scale result to milli-units */
 	val = val * 1000L;

 	if (exponent >= 0)
 		val <<= exponent;
 	else
 		val >>= -exponent;

 	return val;
 }

 #define MAX_MANTISSA	(1023 * 1000)
 #define MIN_MANTISSA	(511 * 1000)

 static u16 zl6100_d2l(long val)
 {
 	s16 exponent = 0, mantissa;
 	bool negative = false;

 	/* simple case */
 	if (val == 0)
 		return 0;

 	if (val < 0) {
 		negative = true;
 		val = -val;
 	}

 	/* Reduce large mantissa until it fits into 10 bit */
 	while (val >= MAX_MANTISSA && exponent < 15) {
 		exponent++;
 		val >>= 1;
 	}
 	/* Increase small mantissa to improve precision */
 	while (val < MIN_MANTISSA && exponent > -15) {
 		exponent--;
 		val <<= 1;
 	}

 	/* Convert mantissa from milli-units to units */
 	mantissa = DIV_ROUND_CLOSEST(val, 1000);

 	/* Ensure that resulting number is within range */
 	if (mantissa > 0x3ff)
 		mantissa = 0x3ff;

 	/* restore sign */
 	if (negative)
 		mantissa = -mantissa;

 	/* Convert to 5 bit exponent, 11 bit mantissa */
 	return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);
 }

 /* Some chips need a delay between accesses */
 static inline void zl6100_wait(const struct zl6100_data *data)
 {
 	if (data->delay) {
 		s64 delta = ktime_us_delta(ktime_get(), data->access);
 		if (delta < data->delay)
 			udelay(data->delay - delta);
 	}
 }

 static int zl6100_read_word_data(struct i2c_client *client, int page,
 				 int phase, int reg)
 {
 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 	struct zl6100_data *data = to_zl6100_data(info);
 	int ret, vreg;

 	if (page >= info->pages)
 		return -ENXIO;

 	if (data->id == zl2005) {
 		/*
 		 * Limit register detection is not reliable on ZL2005.
 		 * Make sure registers are not erroneously detected.
 		 */
 		switch (reg) {
 		case PMBUS_VOUT_OV_WARN_LIMIT:
 		case PMBUS_VOUT_UV_WARN_LIMIT:
 		case PMBUS_IOUT_OC_WARN_LIMIT:
 			return -ENXIO;
 		}
 	}

 	switch (reg) {
 	case PMBUS_VIRT_READ_VMON:
 		vreg = MFR_READ_VMON;
 		break;
 	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 	case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
 		vreg = MFR_VMON_OV_FAULT_LIMIT;
 		break;
 	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 	case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
 		vreg = MFR_VMON_UV_FAULT_LIMIT;
 		break;
 	default:
 		if (reg >= PMBUS_VIRT_BASE)
 			return -ENXIO;
 		vreg = reg;
 		break;
 	}

 	zl6100_wait(data);
 	ret = pmbus_read_word_data(client, page, phase, vreg);
 	data->access = ktime_get();
 	if (ret < 0)
 		return ret;

 	switch (reg) {
 	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 		ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 9, 10));
 		break;
 	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 		ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 11, 10));
 		break;
 	}

 	return ret;
 }

 static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
 {
 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 	struct zl6100_data *data = to_zl6100_data(info);
 	int ret, status;

 	if (page >= info->pages)
 		return -ENXIO;

 	zl6100_wait(data);

 	switch (reg) {
 	case PMBUS_VIRT_STATUS_VMON:
 		ret = pmbus_read_byte_data(client, 0,
 					   PMBUS_STATUS_MFR_SPECIFIC);
 		if (ret < 0)
 			break;

 		status = 0;
 		if (ret & VMON_UV_WARNING)
 			status |= PB_VOLTAGE_UV_WARNING;
 		if (ret & VMON_OV_WARNING)
 			status |= PB_VOLTAGE_OV_WARNING;
 		if (ret & VMON_UV_FAULT)
 			status |= PB_VOLTAGE_UV_FAULT;
 		if (ret & VMON_OV_FAULT)
 			status |= PB_VOLTAGE_OV_FAULT;
 		ret = status;
 		break;
 	default:
 		ret = pmbus_read_byte_data(client, page, reg);
 		break;
 	}
 	data->access = ktime_get();

 	return ret;
 }

 static int zl6100_write_word_data(struct i2c_client *client, int page, int reg,
 				  u16 word)
 {
 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 	struct zl6100_data *data = to_zl6100_data(info);
 	int ret, vreg;

 	if (page >= info->pages)
 		return -ENXIO;

 	switch (reg) {
 	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 		word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 9));
 		vreg = MFR_VMON_OV_FAULT_LIMIT;
 		pmbus_clear_cache(client);
 		break;
 	case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
 		vreg = MFR_VMON_OV_FAULT_LIMIT;
 		pmbus_clear_cache(client);
 		break;
 	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 		word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 11));
 		vreg = MFR_VMON_UV_FAULT_LIMIT;
 		pmbus_clear_cache(client);
 		break;
 	case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
 		vreg = MFR_VMON_UV_FAULT_LIMIT;
 		pmbus_clear_cache(client);
 		break;
 	default:
 		if (reg >= PMBUS_VIRT_BASE)
 			return -ENXIO;
 		vreg = reg;
 	}

 	zl6100_wait(data);
 	ret = pmbus_write_word_data(client, page, vreg, word);
 	data->access = ktime_get();

 	return ret;
 }

 static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
 {
 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 	struct zl6100_data *data = to_zl6100_data(info);
 	int ret;

 	if (page >= info->pages)
 		return -ENXIO;

 	zl6100_wait(data);
 	ret = pmbus_write_byte(client, page, value);
 	data->access = ktime_get();

 	return ret;
 }

 static const struct i2c_device_id zl6100_id[] = {
 	{"bmr450", zl2005},
 	{"bmr451", zl2005},
 	{"bmr462", zl2008},
 	{"bmr463", zl2008},
 	{"bmr464", zl2008},
 	{"bmr465", zls4009},
 	{"bmr466", zls1003},
 	{"bmr467", zls4009},
 	{"bmr469", zl8802},
 	{"zl2004", zl2004},
 	{"zl2005", zl2005},
 	{"zl2006", zl2006},
 	{"zl2008", zl2008},
 	{"zl2105", zl2105},
 	{"zl2106", zl2106},
 	{"zl6100", zl6100},
 	{"zl6105", zl6105},
 	{"zl8802", zl8802},
 	{"zl9101", zl9101},
 	{"zl9117", zl9117},
 	{"zls1003", zls1003},
 	{"zls4009", zls4009},
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, zl6100_id);

 static int zl6100_probe(struct i2c_client *client)
 {
 	int ret, i;
 	struct zl6100_data *data;
 	struct pmbus_driver_info *info;
 	u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
 	const struct i2c_device_id *mid;

 	if (!i2c_check_functionality(client->adapter,
 				     I2C_FUNC_SMBUS_READ_WORD_DATA
 				     | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
 		return -ENODEV;

 	ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
 					device_id);
 	if (ret < 0) {
 		dev_err(&client->dev, "Failed to read device ID\n");
 		return ret;
 	}
 	device_id[ret] = '\0';
 	dev_info(&client->dev, "Device ID %s\n", device_id);

 	mid = NULL;
 	for (mid = zl6100_id; mid->name[0]; mid++) {
 		if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
 			break;
 	}
 	if (!mid->name[0]) {
 		dev_err(&client->dev, "Unsupported device\n");
 		return -ENODEV;
 	}
 	if (strcmp(client->name, mid->name) != 0)
 		dev_notice(&client->dev,
 			   "Device mismatch: Configured %s, detected %s\n",
 			   client->name, mid->name);

 	data = devm_kzalloc(&client->dev, sizeof(struct zl6100_data),
 			    GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	data->id = mid->driver_data;

 	/*
 	 * According to information from the chip vendor, all currently
 	 * supported chips are known to require a wait time between I2C
 	 * accesses.
 	 */
 	data->delay = delay;

 	/*
 	 * Since there was a direct I2C device access above, wait before
 	 * accessing the chip again.
 	 */
 	data->access = ktime_get();
 	zl6100_wait(data);

 	info = &data->info;

 	info->pages = 1;
 	info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
 	  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 	  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 	  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;

 	/*
 	 * ZL2004, ZL8802, ZL9101M, ZL9117M and ZLS4009 support monitoring
 	 * an extra voltage (VMON for ZL2004, ZL8802 and ZLS4009,
 	 * VDRV for ZL9101M and ZL9117M). Report it as vmon.
 	 */
 	if (data->id == zl2004 || data->id == zl8802 || data->id == zl9101 ||
 	    data->id == zl9117 || data->id == zls4009)
 		info->func[0] |= PMBUS_HAVE_VMON | PMBUS_HAVE_STATUS_VMON;

 	/*
 	 * ZL8802 has two outputs that can be used either independently or in
 	 * a current sharing configuration. The driver uses the DDC_CONFIG
 	 * register to check if the module is running with independent or
 	 * shared outputs. If the module is in shared output mode, only one
 	 * output voltage will be reported.
 	 */
 	if (data->id == zl8802) {
 		info->pages = 2;
 		info->func[0] |= PMBUS_HAVE_IIN;

 		ret = i2c_smbus_read_word_data(client, ZL8802_MFR_DDC_CONFIG);
 		if (ret < 0)
 			return ret;

 		data->access = ktime_get();
 		zl6100_wait(data);

 		if (ret & ZL8802_MFR_PHASES_MASK)
 			info->func[1] |= PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
 		else
 			info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 				| PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;

 		for (i = 0; i < 2; i++) {
 			ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
 			if (ret < 0)
 				return ret;

 			data->access = ktime_get();
 			zl6100_wait(data);

 			ret = i2c_smbus_read_word_data(client, ZL8802_MFR_USER_CONFIG);
 			if (ret < 0)
 				return ret;

 			if (ret & ZL8802_MFR_XTEMP_ENABLE_2)
 				info->func[i] |= PMBUS_HAVE_TEMP2;

 			data->access = ktime_get();
 			zl6100_wait(data);
 		}
 		ret = i2c_smbus_read_word_data(client, ZL8802_MFR_USER_GLOBAL_CONFIG);
 		if (ret < 0)
 			return ret;

 		if (ret & ZL8802_MFR_TMON_ENABLE)
 			info->func[0] |= PMBUS_HAVE_TEMP3;
 	} else {
 		ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG);
 		if (ret < 0)
 			return ret;

 		if (ret & ZL6100_MFR_XTEMP_ENABLE)
 			info->func[0] |= PMBUS_HAVE_TEMP2;
 	}

 	data->access = ktime_get();
 	zl6100_wait(data);

 	info->read_word_data = zl6100_read_word_data;
 	info->read_byte_data = zl6100_read_byte_data;
 	info->write_word_data = zl6100_write_word_data;
 	info->write_byte = zl6100_write_byte;

 	return pmbus_do_probe(client, info);
 }

 static struct i2c_driver zl6100_driver = {
 	.driver = {
 		   .name = "zl6100",
 		   },
 	.probe_new = zl6100_probe,
 	.id_table = zl6100_id,
 };

 module_i2c_driver(zl6100_driver);

 MODULE_AUTHOR("Guenter Roeck");
 MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
 MODULE_LICENSE("GPL");
 MODULE_IMPORT_NS(PMBUS);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Hardware monitoring driver for ZL6100 and compatibles
	*
	* Copyright (c) 2011 Ericsson AB.
	* Copyright (c) 2012 Guenter Roeck
	*/

	#include <linux/bitops.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/err.h>
	#include <linux/slab.h>
	#include <linux/i2c.h>
	#include <linux/ktime.h>
	#include <linux/delay.h>
	#include "pmbus.h"

	enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105,
	zl8802, zl9101, zl9117, zls1003, zls4009 };

	struct zl6100_data {
	int id;
	ktime_t access; /* chip access time */
	int delay; /* Delay between chip accesses in uS */
	struct pmbus_driver_info info;
	};

	#define to_zl6100_data(x) container_of(x, struct zl6100_data, info)

	#define ZL6100_MFR_CONFIG 0xd0
	#define ZL6100_DEVICE_ID 0xe4

	#define ZL6100_MFR_XTEMP_ENABLE BIT(7)

	#define ZL8802_MFR_USER_GLOBAL_CONFIG 0xe9
	#define ZL8802_MFR_TMON_ENABLE BIT(12)
	#define ZL8802_MFR_USER_CONFIG 0xd1
	#define ZL8802_MFR_XTEMP_ENABLE_2 BIT(1)
	#define ZL8802_MFR_DDC_CONFIG 0xd3
	#define ZL8802_MFR_PHASES_MASK 0x0007

	#define MFR_VMON_OV_FAULT_LIMIT 0xf5
	#define MFR_VMON_UV_FAULT_LIMIT 0xf6
	#define MFR_READ_VMON 0xf7

	#define VMON_UV_WARNING BIT(5)
	#define VMON_OV_WARNING BIT(4)
	#define VMON_UV_FAULT BIT(1)
	#define VMON_OV_FAULT BIT(0)

	#define ZL6100_WAIT_TIME 1000 /* uS */

	static ushort delay = ZL6100_WAIT_TIME;
	module_param(delay, ushort, 0644);
	MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");

	/* Convert linear sensor value to milli-units */
	static long zl6100_l2d(s16 l)
	{
	s16 exponent;
	s32 mantissa;
	long val;

	exponent = l >> 11;
	mantissa = ((s16)((l & 0x7ff) << 5)) >> 5;

	val = mantissa;

	/* scale result to milli-units */
	val = val * 1000L;

	if (exponent >= 0)
	val <<= exponent;
	else
	val >>= -exponent;

	return val;
	}

	#define MAX_MANTISSA (1023 * 1000)
	#define MIN_MANTISSA (511 * 1000)

	static u16 zl6100_d2l(long val)
	{
	s16 exponent = 0, mantissa;
	bool negative = false;

	/* simple case */
	if (val == 0)
	return 0;

	if (val < 0) {
	negative = true;
	val = -val;
	}

	/* Reduce large mantissa until it fits into 10 bit */
	while (val >= MAX_MANTISSA && exponent < 15) {
	exponent++;
	val >>= 1;
	}
	/* Increase small mantissa to improve precision */
	while (val < MIN_MANTISSA && exponent > -15) {
	exponent--;
	val <<= 1;
	}

	/* Convert mantissa from milli-units to units */
	mantissa = DIV_ROUND_CLOSEST(val, 1000);

	/* Ensure that resulting number is within range */
	if (mantissa > 0x3ff)
	mantissa = 0x3ff;

	/* restore sign */
	if (negative)
	mantissa = -mantissa;

	/* Convert to 5 bit exponent, 11 bit mantissa */
	return (mantissa & 0x7ff) \| ((exponent << 11) & 0xf800);
	}

	/* Some chips need a delay between accesses */
	static inline void zl6100_wait(const struct zl6100_data *data)
	{
	if (data->delay) {
	s64 delta = ktime_us_delta(ktime_get(), data->access);
	if (delta < data->delay)
	udelay(data->delay - delta);
	}
	}

	static int zl6100_read_word_data(struct i2c_client *client, int page,
	int phase, int reg)
	{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct zl6100_data *data = to_zl6100_data(info);
	int ret, vreg;

	if (page >= info->pages)
	return -ENXIO;

	if (data->id == zl2005) {
	/*
	* Limit register detection is not reliable on ZL2005.
	* Make sure registers are not erroneously detected.
	*/
	switch (reg) {
	case PMBUS_VOUT_OV_WARN_LIMIT:
	case PMBUS_VOUT_UV_WARN_LIMIT:
	case PMBUS_IOUT_OC_WARN_LIMIT:
	return -ENXIO;
	}
	}

	switch (reg) {
	case PMBUS_VIRT_READ_VMON:
	vreg = MFR_READ_VMON;
	break;
	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
	case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
	vreg = MFR_VMON_OV_FAULT_LIMIT;
	break;
	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
	case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
	vreg = MFR_VMON_UV_FAULT_LIMIT;
	break;
	default:
	if (reg >= PMBUS_VIRT_BASE)
	return -ENXIO;
	vreg = reg;
	break;
	}

	zl6100_wait(data);
	ret = pmbus_read_word_data(client, page, phase, vreg);
	data->access = ktime_get();
	if (ret < 0)
	return ret;

	switch (reg) {
	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
	ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 9, 10));
	break;
	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
	ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 11, 10));
	break;
	}

	return ret;
	}

	static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
	{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct zl6100_data *data = to_zl6100_data(info);
	int ret, status;

	if (page >= info->pages)
	return -ENXIO;

	zl6100_wait(data);

	switch (reg) {
	case PMBUS_VIRT_STATUS_VMON:
	ret = pmbus_read_byte_data(client, 0,
	PMBUS_STATUS_MFR_SPECIFIC);
	if (ret < 0)
	break;

	status = 0;
	if (ret & VMON_UV_WARNING)
	status \|= PB_VOLTAGE_UV_WARNING;
	if (ret & VMON_OV_WARNING)
	status \|= PB_VOLTAGE_OV_WARNING;
	if (ret & VMON_UV_FAULT)
	status \|= PB_VOLTAGE_UV_FAULT;
	if (ret & VMON_OV_FAULT)
	status \|= PB_VOLTAGE_OV_FAULT;
	ret = status;
	break;
	default:
	ret = pmbus_read_byte_data(client, page, reg);
	break;
	}
	data->access = ktime_get();

	return ret;
	}

	static int zl6100_write_word_data(struct i2c_client *client, int page, int reg,
	u16 word)
	{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct zl6100_data *data = to_zl6100_data(info);
	int ret, vreg;

	if (page >= info->pages)
	return -ENXIO;

	switch (reg) {
	case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
	word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 9));
	vreg = MFR_VMON_OV_FAULT_LIMIT;
	pmbus_clear_cache(client);
	break;
	case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
	vreg = MFR_VMON_OV_FAULT_LIMIT;
	pmbus_clear_cache(client);
	break;
	case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
	word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 11));
	vreg = MFR_VMON_UV_FAULT_LIMIT;
	pmbus_clear_cache(client);
	break;
	case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
	vreg = MFR_VMON_UV_FAULT_LIMIT;
	pmbus_clear_cache(client);
	break;
	default:
	if (reg >= PMBUS_VIRT_BASE)
	return -ENXIO;
	vreg = reg;
	}

	zl6100_wait(data);
	ret = pmbus_write_word_data(client, page, vreg, word);
	data->access = ktime_get();

	return ret;
	}

	static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
	{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct zl6100_data *data = to_zl6100_data(info);
	int ret;

	if (page >= info->pages)
	return -ENXIO;

	zl6100_wait(data);
	ret = pmbus_write_byte(client, page, value);
	data->access = ktime_get();

	return ret;
	}

	static const struct i2c_device_id zl6100_id[] = {
	{"bmr450", zl2005},
	{"bmr451", zl2005},
	{"bmr462", zl2008},
	{"bmr463", zl2008},
	{"bmr464", zl2008},
	{"bmr465", zls4009},
	{"bmr466", zls1003},
	{"bmr467", zls4009},
	{"bmr469", zl8802},
	{"zl2004", zl2004},
	{"zl2005", zl2005},
	{"zl2006", zl2006},
	{"zl2008", zl2008},
	{"zl2105", zl2105},
	{"zl2106", zl2106},
	{"zl6100", zl6100},
	{"zl6105", zl6105},
	{"zl8802", zl8802},
	{"zl9101", zl9101},
	{"zl9117", zl9117},
	{"zls1003", zls1003},
	{"zls4009", zls4009},
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, zl6100_id);

	static int zl6100_probe(struct i2c_client *client)
	{
	int ret, i;
	struct zl6100_data *data;
	struct pmbus_driver_info *info;
	u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
	const struct i2c_device_id *mid;

	if (!i2c_check_functionality(client->adapter,
	I2C_FUNC_SMBUS_READ_WORD_DATA
	\| I2C_FUNC_SMBUS_READ_BLOCK_DATA))
	return -ENODEV;

	ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
	device_id);
	if (ret < 0) {
	dev_err(&client->dev, "Failed to read device ID\n");
	return ret;
	}
	device_id[ret] = '\0';
	dev_info(&client->dev, "Device ID %s\n", device_id);

	mid = NULL;
	for (mid = zl6100_id; mid->name[0]; mid++) {
	if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
	break;
	}
	if (!mid->name[0]) {
	dev_err(&client->dev, "Unsupported device\n");
	return -ENODEV;
	}
	if (strcmp(client->name, mid->name) != 0)
	dev_notice(&client->dev,
	"Device mismatch: Configured %s, detected %s\n",
	client->name, mid->name);

	data = devm_kzalloc(&client->dev, sizeof(struct zl6100_data),
	GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	data->id = mid->driver_data;

	/*
	* According to information from the chip vendor, all currently
	* supported chips are known to require a wait time between I2C
	* accesses.
	*/
	data->delay = delay;

	/*
	* Since there was a direct I2C device access above, wait before
	* accessing the chip again.
	*/
	data->access = ktime_get();
	zl6100_wait(data);

	info = &data->info;

	info->pages = 1;
	info->func[0] = PMBUS_HAVE_VIN \| PMBUS_HAVE_STATUS_INPUT
	\| PMBUS_HAVE_VOUT \| PMBUS_HAVE_STATUS_VOUT
	\| PMBUS_HAVE_IOUT \| PMBUS_HAVE_STATUS_IOUT
	\| PMBUS_HAVE_TEMP \| PMBUS_HAVE_STATUS_TEMP;

	/*
	* ZL2004, ZL8802, ZL9101M, ZL9117M and ZLS4009 support monitoring
	* an extra voltage (VMON for ZL2004, ZL8802 and ZLS4009,
	* VDRV for ZL9101M and ZL9117M). Report it as vmon.
	*/
	if (data->id == zl2004 \|\| data->id == zl8802 \|\| data->id == zl9101 \|\|
	data->id == zl9117 \|\| data->id == zls4009)
	info->func[0] \|= PMBUS_HAVE_VMON \| PMBUS_HAVE_STATUS_VMON;

	/*
	* ZL8802 has two outputs that can be used either independently or in
	* a current sharing configuration. The driver uses the DDC_CONFIG
	* register to check if the module is running with independent or
	* shared outputs. If the module is in shared output mode, only one
	* output voltage will be reported.
	*/
	if (data->id == zl8802) {
	info->pages = 2;
	info->func[0] \|= PMBUS_HAVE_IIN;

	ret = i2c_smbus_read_word_data(client, ZL8802_MFR_DDC_CONFIG);
	if (ret < 0)
	return ret;

	data->access = ktime_get();
	zl6100_wait(data);

	if (ret & ZL8802_MFR_PHASES_MASK)
	info->func[1] \|= PMBUS_HAVE_IOUT \| PMBUS_HAVE_STATUS_IOUT;
	else
	info->func[1] = PMBUS_HAVE_VOUT \| PMBUS_HAVE_STATUS_VOUT
	\| PMBUS_HAVE_IOUT \| PMBUS_HAVE_STATUS_IOUT;

	for (i = 0; i < 2; i++) {
	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
	if (ret < 0)
	return ret;

	data->access = ktime_get();
	zl6100_wait(data);

	ret = i2c_smbus_read_word_data(client, ZL8802_MFR_USER_CONFIG);
	if (ret < 0)
	return ret;

	if (ret & ZL8802_MFR_XTEMP_ENABLE_2)
	info->func[i] \|= PMBUS_HAVE_TEMP2;

	data->access = ktime_get();
	zl6100_wait(data);
	}
	ret = i2c_smbus_read_word_data(client, ZL8802_MFR_USER_GLOBAL_CONFIG);
	if (ret < 0)
	return ret;

	if (ret & ZL8802_MFR_TMON_ENABLE)
	info->func[0] \|= PMBUS_HAVE_TEMP3;
	} else {
	ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG);
	if (ret < 0)
	return ret;

	if (ret & ZL6100_MFR_XTEMP_ENABLE)
	info->func[0] \|= PMBUS_HAVE_TEMP2;
	}

	data->access = ktime_get();
	zl6100_wait(data);

	info->read_word_data = zl6100_read_word_data;
	info->read_byte_data = zl6100_read_byte_data;
	info->write_word_data = zl6100_write_word_data;
	info->write_byte = zl6100_write_byte;

	return pmbus_do_probe(client, info);
	}

	static struct i2c_driver zl6100_driver = {
	.driver = {
	.name = "zl6100",
	},
	.probe_new = zl6100_probe,
	.id_table = zl6100_id,
	};

	module_i2c_driver(zl6100_driver);

	MODULE_AUTHOR("Guenter Roeck");
	MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
	MODULE_LICENSE("GPL");
	MODULE_IMPORT_NS(PMBUS);